9x-5y+z=5(1)
9x+y+4z=14(2)
-9x+3y-5z=-11(3)
(1)-(2)
-6y-3z=-9
2y+z=3
z=3-2y(4)
(2)+(3)
4y-z=3
4y+2y-3=3
6y=6
y=1
z=3-2y=3-2=1
9x-5+1=5
9x=9
x=1
x=1
y=1
z=1